Brad,
So, I just took a quick skim of the mpdpup stuff and it looks interesting, but it appears to be targetted at folks who don't want to learn linux internals and such as it provides wizzards, GUI tools and other things that are really of no use to me personally. And the playback software remains MPD. So, while I have no interest in this personally, it could be a great place for people not comfortable with linux and device/network configuration to get going with this stuff.
The GUI stuff is not accessible to me anyway, so I apologize but I will not be able to help others through this, as much as I would like to help.
In the mean time, I've been looking at some of the options in front of me, and I see some great places for the RPi and some places for the alix, and I now really want to build a NAS based system with the alix, SOTM usbx card SOTM battery supply, and separate linear regulated supplies for the alix card and the mini-pci to pcie card. All this looks like it will support PCM and DSD with DoP 1.0 and thus could be a really great server for my Sonore usb/dsd dac.
I also just noticed that the Voyage folks have a new usb to I2S/spdif interface card, so there is yet another possiblity for the BH dac and others with no usb, or usb 1.1 only connectivity.
I also just got, as part of a trade, a 3 meter, brand new WireWorld Starlight 3.0 usb cable -- wow, what a nice thing this is -- heavy duty comes to ind here as it is close to 3/4" wide but in the same flat-ish cable config that the other WW usb cables are. And it's backwards compatible. So, why the usb 3.0 if I'm only running 2.0 capable devices? Well, because it didn't cost me anything, and at least on paper, the conductors and shielding seem to be more robust, and I don't think that can really hurt anyting, and may even be an upgrade. Should find out this weekend.
Again, I'd really encrourage those who are curious about this stuff to look at the MPDpup distro -- it may be just what lots of folks will want. Lots of info, including the presence of the developer, on computeraudiophile.com
-- Jim